Furnace



March 25, 1930. CJJ. HUBER FURNACE March 25, 1930. c. J. HUBER FURNACE Fild June 2, 1925 3 Sheets$heet 2 if i1 M t n C. J. HUBER Mrch 25, 1930.

FURNACE 3 Sheets-Sheet 3 Filed June 2, 1925 Patented Mar. 25, 1930 UNITED STATES PATENT OFFICE CHARLES J. HUBER, OF BALTIMORE,- MARYLAND, ASSIGNOR OF ONE-HALF TO FLYNN AND EMRICH COMPANY, OF BALTIMORE, MARYLAND, CORPORATION OF MARY- LAND FURNACE Application filed June 2, 1925. Serial No. 34,312.

The invention relates to an improvement in and to the furnace structure of my United States Patent No. 1,499,532, granted July 1, 192 1. The improvement is directed at the further economy of the fuel, elimination of smoke and noxious gases, and at the cooling of the beams which support the arch structure.

The smoke and gases comprising finely divided carbon, hydrocarbons and the lower oxides of carbon which escape from power plant furnaces through the flue, not only represent considerable fuel losses, but constitute a nuisance to all residents and businesses in the vicinity. The objectionable effect is not limited to the immediate vicinity, as the smoke, i. e., carbon particles and to some extent the gases, are frequently carried by the wind to considerable distances.

The object of the construction shown and claimed in the above-cited patent is to achieve economy by providing for complete combustion of the coal, eliminating smoke and unconsumed gases by burning them in the furnace. The coal is coked at the .front of the furnace before it is fed to the fire, and the vapors from the coal are mixed with air burned in the furnace. Coking is performed on a coking shelf of refractory material, as firebrick, at the front of the furnace above the fire, and there is a reflecting member of heat-storing refractory material above the coking shelf. In accordance with the structure shown in the patent, air is admitted at the front, generally from the fire box heneath the shelf and forward of the coal dropped from the shelf so as not to be choked by the fuel and so that the smoke and gases released in coking are mingled with the air and burned as they pass over the fire toward the bridge wall. All of the volatile elements of the coal are driven ofi-at the front of the furnace and mingled with air freely ad mitted at the extreme forward end of the furnace and beneath the coking shelf. By this method of volatilization and combination with air at the front of the furnace, increased eficiency in the way of complete combustion, generation of heat and smoke prevention attained The present improvement is in the nature of the addition of a new feature to the structure of the aforesaid patent, the theory and operation of which have just been outlined.

The admission of air in -the manner described in the patent and the mingling of the same with the vapors distilled from the coal on the coking shelf at the high temperature maintained immediately over and on the coking shelf and throughout the furnace, assists in the accomplishment of the objects stated, glvmg more complete combustion and very little smoke than previously but a much more perfect result is attained withoutincreased expense by introducing at the front of the furnace an air supply which is highly heated without proportionate loss of heat units from the furnace, the mixture of an excess of heated air with the vapors from the coal being coked at the front of the furnace immediately on the release of these vapors from the coal gives absolutely complete combustion in every instance with no smoke at all, even after the introduction of green fuel, and further increased generation of heat on account of the complete combustion and the economy of heat units efiected by introducing heated air. Also the arch supporting beams being utilized as the side walls of the air passage, are beneficially cboled, preventing their deterioration as a result of exposure to the heat of the furnace, as conducted to them through the arch.

The features of the apparatus on Which the results thus outlined are dependent and the details of the structure in connection with which these features have been developed, are illustrated in theaccompanying drawings.

In the drawingsa Figure 1 is a section taken transversely of the furnace arch and coking shelf, showing the hopper opening to the furnace, the section being a fragmentary view at the front of the furnace in a plane extending longitudi- Figure 3 is a section on the line 3, 3 Figure 2.

Figure 4 is a front elevation of the furnace.

In the specification and claims the term front is applied to the side or end of the furnace shown in Figure 4, known in the trade as the furnace front. This is where the operator stands. In the operation of this furnace, as in that of the Huber patent cited herein, the fuel is fed backwardly toward the arch.

Referring to the drawings by numerals, each of Wl'llCh is used to indicate the same or similar parts in the different figures, the

structure as shown comprises a furnace struc-' ture 1, more fully illustrated in Figure 1 of the patent referred to, having an arch structure 2 built up of fire brick, as illustrated, and supported by transverse beams 3, shown in the form of channels, which might also be described as semi-I beams. Beams of any desired cross-section may be used for this purpose, those having channels in the sides ei her formed in the integral beam structure or built up being preferable for the present purpose. The channels 3. as shown, are spaced apart to form an air passage 4 extending transversely of the furnace and are supported on the furnace walls in any convement and suitable manner in accordance with the present or any preferred practice in the construction of furnaces, an important consideration being that the beams are-exposed as to their ends which are open at the sides of the furnace or some opening is provided for the admission of air to the transverse passage thus formed between the beams. The arch 2 is formed, as shown, with I upwardly and rearwardly inclined bottom reflecting surfaces 5, 6 which may to advantage be curved and flared outwardly and rearwardly from the hopper opening 7 as shown. This reflecting surface corresponds to the top reflecting surface of the hopper opening shown in the aforementioned patent, and is formed of firebricks 8, 9 supported in any suitable manner from the transverse beams 3, as by means of hooks 10 placed at intervals between the channels on the bottom flanges of-which the arms 11 of the hooks rest, which hooks have depending flanged portions 12 which engage suitable grooves 13 in the firebricks. At the bottom of the hopper opening is a transverse firebrickshelf 14 referred to herein and previously as a coking shelf, both the coking shelf as to its front and bottom surfaces and the reflecting member 5, 6 receive the direct radiation from the fire as does the pile of coke 16 on the shelf which likewise receives the heat transmitted from the coking shelf and reflected from the reflecting surface 5, 6 of the arch. The heat transmitted to the arch by the fire is also carried upwardly by conduction, raising the temperature of the supporting beam 3 at the cooling of which, various attempts in furnace desi have been previous] directed, the beams i a wing been ventilate by numerous diiferentdevices not entirely satisfactory.

In the present structure air passages 20 lead from the transverse air passage 4 between the beams 3 downwardly between the hooks 10 and forwardly over the firebricks 8 which form the bottom of the arch and the top of the hopper opening, through openings 21 in the front plate 22 of the furnace, which openings are in the preferred form of the invention shown, controlled by a draft shutter 24 having draft openings 25 registering in the open position of the draft with the openings 21 which slide on a ledge 26 formed for this purpose on the plate 22. From the draft openings 25 the air enters the downward passage 27, which in the form of the invention shown is located between the rear wall 28 of the hopper 29 and the front plate 22 of the arch. The down passage 27 thus described, in the form of the invention shown opens into the top of the hopper'feed opening 30. In the preferred form, as illustrated, there is a hopper opening shutter 31 mounted on the rear wall of the hopper by means of bolts 32 tightened by butterfly nuts 33 which engage vertical slots 34 in the hopper wall, providing for adjustment of the shutter 31 in a corresponding direction.

As shown, the shutter is further provided at its bottom edge with a lip 36 having a downwardly and rearwardly inclined top surface 37 which acts as a deflecting surface, turning the delivery opening of the passage inwardly toward'the furnace, and so placing the delivery opening 38 of the assage by turning it to the rear as to avoid locking of the passage by accumulation of fuel, the fuel on the coking shelf normally assuming an inclinationas to its top surface downwardly and inwardly from the bottom of-the lip 37 to the rear top edge 41 of the coking shelf leaving the passage open. The operation will be easily understood from the description of the furnace structure. The heat of the fire establishes by means of the stack, or a mechanical draft, suflicient minus pressure below atmosphere or difference of pressure to maintain a current of air entering at 42, Fig. 4, into the passage 4 between the beams 3, which current of air being'suitably divided enters the passages 20 between the hooks 10 and passes over the bottom bricks 8, 9 of the arch, which passages lead by way of openings 21 and draft openings 25 into the down passages 27 through which the air is drawn by the suction or minus pressure in the furnace or by means of any draft created in any manner. The air thus introduced is delivered directly upon and in contact with the surface of the pile 16 of fuel posed of inflammable gases and carbon the diate current of heated air is ready for imme tions of adjustment to control the size of i the hopper openin'g,-the plate forming a baf- He at one side of the air current whereby the hot" air from the passage is directed into immediate contact with the enterin fuel.

Signed by me at Baltimore, Mary and, this 29 day of May, 1925. A p

- CHARLES J.

combination with the vapors, and in its pasj sage through the furnace combines with and completely oxidizes these gases and all burnable materials given oil by the fuel, so that complete combustion is attained at all times, even during stoking, and the liberation of smoke and noxious gases is wholly avoided,

The device thus described hasthe further advantages of cooling most efiiciently "and preventing deterioration of the beams 3 which support the arch and form the walls of the transverse air passa e 4 and the rear wall 28 of the hopper, whic beingin immediate contact with the fuel, is to the best advantage ke t at a low temperature to avoid premature 'stillation of the volatile contents of the fuel and the presence of gaseous vapors in the boiler room.

- I have thus described specifically and in detail a single embodiment of my invention in order that thenature and operation of v the same may be clearly understood howthe arch, the

ever, the specific terms herein are used descriptively rather than in a limiting" sense,

.the scope of the invention being defined in the claims.

What I claim and desire to secure by Letters Patent is: I

1. In afurnace having1 a hopper with a hopper openi an are extending rearwardly from a ve-the hopper opening, a

coking shelf extending rearwardly from bene'ath the hopper opening an air passage in the arch, the hopper having a double rear wall providing an air passage therein connected to the arch passa e leading downward to the hopper opening into which itdischarges, and an adjusting plate'to control the size of the hopper opening, with means for securing-the same in various positions of adjustment, said plate having a lip to deflect the air from said passagesbackward into the combustion space of the furnace '2. In a furnace ha "a hopper witha hopper openin an are extending rear wardly from a ve the hopper opening, a coking shelf extending rearwardiy from'be neath the hoppler opening, an air passage in opper' having a double wall providing an air passe e therein connected to the arch passage an (leading downward to the hopper opening into which it discharges, an adjusting plate in the wall of said passage on the side toward the hopper, meansfer securing the same in various posi- 

